How to Ventilate an Attic to Prevent Mold and Ice Dams
Every attic needs adequate air exchange. The attic ventilation system facilitates the airflow process. Hot air is designed to flow out of the attic, while fresh, cool air enters.
A well-ventilated attic prevents ice dams from forming in winter, as the inflow of cold, outdoor air keeps the attic cold. However, an attic that remains warm allows snow to melt off the roof and refreeze, resulting in ice dams that can damage the rooftop.
In summer, the hot attic air flows out. As a result of super-heated air being ventilated out of the attic, the roof shingles are protected from becoming brittle and ineffective. Lowering the attic temperature extends the roof’s lifespan. Plus, hot air will not seep into the home’s living quarters.
Preventing mold growth is a third benefit of a properly ventilated attic. Buildups of condensation and moisture are likely in attics where drier outside air fails to flow out of the area. Mold colonies flourish in unventilated attics where abundant moisture collects.
Improving the lifespan of the home and reducing energy costs are clear advantages of ventilating the attic.
In order for a homeowner to begin a ventilation project, it is important to know the answers to common questions, such as how much ventilation the attic needs.
Ventilating the attic may be accomplished in the three steps that follow:
Step 1: Determine the required amount of attic ventilation
The amount of attic ventilation necessary is determined by calculating the attic’s square footage (the length multiplied by the width of the attic floor). In attics without a vapor barrier, for every 150 square feet of attic floor space, factor in one square foot of Net Free Area (NFA).
The NFA is the amount of space that allows air to freely flow in or out. Some attic floors feature a vapor barrier. In properties built with a vapor barrier, the homeowner will require one square foot of NFA per 300 square feet of attic flooring.
The best ventilation system allows cool, dry air into the attic at the lowest point. Warm, moist air is removed through the exhaust vents in the attic on the underside of the roof deck. Ideally, aim for a balance of 50 percent intake and 50 percent exhaust.
When the recommended balance cannot be achieved, more intake than exhaust is advised. A property that is built with more exhaust than intake vents will face problems, since the exhaust vents could start to work as intake vents to compensate for the imbalance.
Step 2: Ensure the right number of exhaust vents
The exhaust vents should not exceed the number of intake vents, as mentioned. It is acceptable, however, to use a large number of the same types of exhaust vents. Potential problems arise when adding a combination of different types of exhaust vents in the attic.
Homeowners have five types of exhaust vents from which to choose: ridge vents, power fans, wind turbines, gable louvers and roof louvers. Combining more than two different categories of exhaust vents on a single roof is likely to short-circuit the attic ventilation system.
Warm air rises, and homeowners are advised to take advantage of this buoyancy. Homes are typically filled with warm air due to occupants showering and cooking on a daily basis. Plan to install the intake roof vents close to the eaves and the exhaust vents near the peak.
Step 3: Install the intake and exhaust vents
Upon knowing the preferred types of vents, installing the vents is the next step. Soffit vents are among the most popular styles of intake vents. This type of intake vent allows airflow into the attic while keeping out debris and pests and offering protection against harsh weather conditions.
Mark the vent size. Between the rafters, cut a hole approximately two inches shorter and narrower than the vent itself. Installation may be completed with screws that fasten the vent. Be sure to clear away any debris or insulation that could potentially block the ventilation holes.
Exhaust vents, specifically ridge vents, are installed on the ridge of the roof. A professional roofer will cut away the sheathing and, upon removal of the piece, will install the ridge vent. The ridge vent will be weatherproofed and subsequently secured with nails.
Alternate categories of exhaust vents are available and require different installation methods. Static vents are installed differently than gable vents or turbine vents. In any case, exhaust vent installation is best handled by a roofing contractor, as mistakes can lead to roof leaks and other hazardous outcomes.
Proper attic ventilation will ensure that the space does not exude a musty odor. If musty attic smells occur, inadequate ventilation may be the culprit. Additionally, a home’s roof will perform optimally in the long run when the attic beneath it is built with sufficient ventilation.
Professional Attic Mold Remediation
It is worth noting again that attempting to ventilate the attic without professional assistance from a roofing contractor can lead to moisture intrusions and subsequent mold growth. When you are faced with a mold issue, whether from a roof leak, flood or plumbing issue, call ServiceMaster by Timeless.
A mold invasion, which can begin within 24 hours of a leak, must be addressed promptly by mold remediation professionals. Delaying the cleanup of mold growth can lead to structural issues, since mold eats away at organic materials, like wood and drywall. Mold also causes adverse health reactions.
ServiceMaster by Timeless technicians arrive immediately after your call to assess the extent of mold damage and develop a mold remediation plan. We use accurate mold detection technology to pinpoint all mold growth, including infestations in concealed areas, such as behind the walls or wallpaper.
Our experienced mold cleanup specialists eliminate all mold and remove damaged materials. We disinfect the property, conduct a closing inspection and measure final spore levels.
If your Parsippany-Troy Hills, New Jersey home has a mold issue, call ServiceMaster by Timeless at (973) 554-3002 for certified mold removal.